well... you're able to play any game with the exception of one or two new ones that come with a new protection. And it's your only choice.
For your situation it's a good flashcart. But it's not the best one generally.
Keep in mind as well that you can't safely play online with it since you might get banned. The template Sky3DS uses to run games includes an header (piece of code necessary to play online) but since anyone can use it, Nintendo also knows and can ban you if it detects you online with it. In order to play online safely with Sky3DS, you would need a private header which you can get by extracting it from an original game cartridge. And in your situation, the only way to do it is with a device called powersaves. There's a guide here in the forum on how to do that.
Thanks that keeps me informed. Might as well give up on it then. Assuming I do not go online ninty will never catch me. But I do not like getting banned since I have my wii-u as well on my mii linked and such, same nintendo account. Would suck if I can't play splatoon anymore. I would just play offline games then, but not sure if I can get caught. As for powersaves you mean the datel thing? I have that one.